Index: django/db/models/manager.py =================================================================== --- django/db/models/manager.py (revision 4828) +++ django/db/models/manager.py (working copy) @@ -99,6 +99,9 @@ def order_by(self, *args, **kwargs): return self.get_query_set().order_by(*args, **kwargs) + def select_for_update(self, *args, **kwargs): + return self.get_query_set().select_for_update(*args, **kwargs) + def select_related(self, *args, **kwargs): return self.get_query_set().select_related(*args, **kwargs) Index: django/db/models/query.py =================================================================== --- django/db/models/query.py (revision 4828) +++ django/db/models/query.py (working copy) @@ -82,16 +82,17 @@ def __init__(self, model=None): self.model = model self._filters = Q() - self._order_by = None # Ordering, e.g. ('date', '-name'). If None, use model's ordering. - self._select_related = False # Whether to fill cache for related objects. - self._max_related_depth = 0 # Maximum "depth" for select_related - self._distinct = False # Whether the query should use SELECT DISTINCT. - self._select = {} # Dictionary of attname -> SQL. - self._where = [] # List of extra WHERE clauses to use. - self._params = [] # List of params to use for extra WHERE clauses. - self._tables = [] # List of extra tables to use. - self._offset = None # OFFSET clause. - self._limit = None # LIMIT clause. + self._order_by = None # Ordering, e.g. ('date', '-name'). If None, use model's ordering. + self._select_for_update = False # Whether to select for update. + self._select_related = False # Whether to fill cache for related objects. + self._max_related_depth = 0 # Maximum "depth" for select_related + self._distinct = False # Whether the query should use SELECT DISTINCT. + self._select = {} # Dictionary of attname -> SQL. + self._where = [] # List of extra WHERE clauses to use. + self._params = [] # List of params to use for extra WHERE clauses. + self._tables = [] # List of extra tables to use. + self._offset = None # OFFSET clause. + self._limit = None # LIMIT clause. self._result_cache = None ######################## @@ -211,6 +212,7 @@ counter = self._clone() counter._order_by = () + counter._select_for_update = False counter._select_related = False offset = counter._offset @@ -316,6 +318,7 @@ del_query = self._clone() # disable non-supported fields + del_query._select_for_update = False del_query._select_related = False del_query._order_by = [] @@ -398,6 +401,10 @@ else: return self._filter_or_exclude(None, **filter_obj) + def select_for_update(self, true_or_false=True): + "Returns a new QuerySet instance with '_select_for_update' modified." + return self._clone(_select_for_update=true_or_false) + def select_related(self, true_or_false=True, depth=0): "Returns a new QuerySet instance with '_select_related' modified." return self._clone(_select_related=true_or_false, _max_related_depth=depth) @@ -433,6 +440,7 @@ c.model = self.model c._filters = self._filters c._order_by = self._order_by + c._select_for_update = self._select_for_update c._select_related = self._select_related c._max_related_depth = self._max_related_depth c._distinct = self._distinct @@ -549,6 +557,10 @@ else: assert self._offset is None, "'offset' is not allowed without 'limit'" + # FOR UPDATE + if self._select_for_update: + sql.append("%s" % backend.get_for_update_sql()) + return select, " ".join(sql), params class ValuesQuerySet(QuerySet): Index: django/db/backends/ado_mssql/base.py =================================================================== --- django/db/backends/ado_mssql/base.py (revision 4828) +++ django/db/backends/ado_mssql/base.py (working copy) @@ -116,6 +116,9 @@ if lookup_type=='day': return "Convert(datetime, Convert(varchar(12), %s))" % field_name +def get_for_update_sql(): + return 'WITH (UPDLOCK, HOLDLOCK)' + def get_limit_offset_sql(limit, offset=None): # TODO: This is a guess. Make sure this is correct. sql = "LIMIT %s" % limit Index: django/db/backends/mysql_old/base.py =================================================================== --- django/db/backends/mysql_old/base.py (revision 4828) +++ django/db/backends/mysql_old/base.py (working copy) @@ -166,6 +166,9 @@ sql = "CAST(DATE_FORMAT(%s, '%s') AS DATETIME)" % (field_name, format_str) return sql +def get_for_update_sql(): + return 'FOR UPDATE' + def get_limit_offset_sql(limit, offset=None): sql = "LIMIT " if offset and offset != 0: Index: django/db/backends/postgresql/base.py =================================================================== --- django/db/backends/postgresql/base.py (revision 4828) +++ django/db/backends/postgresql/base.py (working copy) @@ -137,6 +137,9 @@ # http://www.postgresql.org/docs/8.0/static/functions-datetime.html#FUNCTIONS-DATETIME-TRUNC return "DATE_TRUNC('%s', %s)" % (lookup_type, field_name) +def get_for_update_sql(): + return 'FOR UPDATE' + def get_limit_offset_sql(limit, offset=None): sql = "LIMIT %s" % limit if offset and offset != 0: Index: django/db/backends/sqlite3/base.py =================================================================== --- django/db/backends/sqlite3/base.py (revision 4828) +++ django/db/backends/sqlite3/base.py (working copy) @@ -131,6 +131,10 @@ # sqlite doesn't support DATE_TRUNC, so we fake it as above. return 'django_date_trunc("%s", %s)' % (lookup_type.lower(), field_name) +def get_for_update_sql(): + # sqlite does not support FOR UPDATE + return '' + def get_limit_offset_sql(limit, offset=None): sql = "LIMIT %s" % limit if offset and offset != 0: Index: django/db/backends/mysql/base.py =================================================================== --- django/db/backends/mysql/base.py (revision 4828) +++ django/db/backends/mysql/base.py (working copy) @@ -164,6 +164,9 @@ sql = "CAST(DATE_FORMAT(%s, '%s') AS DATETIME)" % (field_name, format_str) return sql +def get_for_update_sql(): + return 'FOR UPDATE' + def get_limit_offset_sql(limit, offset=None): sql = "LIMIT " if offset and offset != 0: Index: django/db/backends/oracle/base.py =================================================================== --- django/db/backends/oracle/base.py (revision 4828) +++ django/db/backends/oracle/base.py (working copy) @@ -101,6 +101,9 @@ def get_date_trunc_sql(lookup_type, field_name): return "EXTRACT(%s FROM TRUNC(%s))" % (lookup_type, field_name) +def get_for_update_sql(): + return 'FOR UPDATE' + def get_limit_offset_sql(limit, offset=None): # Limits and offset are too complicated to be handled here. # Instead, they are handled in django/db/query.py. Index: django/db/backends/postgresql_psycopg2/base.py =================================================================== --- django/db/backends/postgresql_psycopg2/base.py (revision 4828) +++ django/db/backends/postgresql_psycopg2/base.py (working copy) @@ -97,6 +97,9 @@ # http://www.postgresql.org/docs/8.0/static/functions-datetime.html#FUNCTIONS-DATETIME-TRUNC return "DATE_TRUNC('%s', %s)" % (lookup_type, field_name) +def get_for_update_sql(): + return 'FOR UPDATE' + def get_limit_offset_sql(limit, offset=None): sql = "LIMIT %s" % limit if offset and offset != 0: Index: django/db/backends/dummy/base.py =================================================================== --- django/db/backends/dummy/base.py (revision 4828) +++ django/db/backends/dummy/base.py (working copy) @@ -34,6 +34,7 @@ get_last_insert_id = complain get_date_extract_sql = complain get_date_trunc_sql = complain +get_for_update_sql = complain get_limit_offset_sql = complain get_random_function_sql = complain get_deferrable_sql = complain